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<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 猴子摘桃，猴子摘了x个桃，每天吃一半，再多吃一个，第7天吃的时候剩下一个了，猴子摘了多少桃子？ -->
    <script>
        var sum=1;
        for(var a=1;a<7;a++){
sum=(1+sum)*2;
        }
      console.log(sum);
    </script>
</body>
</html>
